Material removal device having improved material capture efficiency and methods of use

Abstract

The present invention provides an improved atherectomy catheter having means for directing particles generated by a cutting element into a collection chamber. Methods of directing the cut material from a blood vessel lumen into a collection chamber are also provided.

1 . An atherectomy catheter, comprising:
 a body having an opening;   a rotatable shaft coupled to the body;   a tissue collection chamber coupled to the body and positioned distal to the cutting element;   a cutting element coupled to the rotatable shaft, the cutting element having a cutting edge; and   a lumen configured to direct fluid into the tissue collection chamber.   
     
     
         2 . The catheter of  claim 1 , wherein the lumen directs fluid in a distal direction into the tissue collection chamber. 
     
     
         3 . The catheter of  claim 1 , wherein the cutting element has a cup-shaped surface, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction. 
     
     
         4 . The catheter of  claim 3 , wherein the lumen has a distal opening on the cup-shaped surface of the cutting element. 
     
     
         5 . The catheter of  claim 4 , wherein the lumen comprises a first lumen portion in the cutting element and a second lumen portion in the rotatable shaft. 
     
     
         6 . The catheter of  claim 4 , wherein the distal opening is positioned at a longitudinal axis of the cutting element. 
     
     
         7 . The catheter of  claim 3 , wherein the lumen has a distal opening and the distal opening is not positioned on the cup-shaped surface of the cutting element. 
     
     
         8 . The catheter of  claim 7 , wherein the distal opening is positioned adjacent to the cup-shaped surface of the cutting element. 
     
     
         9 . The catheter of  claim 1 , wherein a fluid source that supplies fluid to the lumen is attached to a proximal portion of the catheter. 
     
     
         10 . The catheter of  claim 9 , wherein the fluid supplied by the fluid source is a saline solution. 
     
     
         11 . The catheter of  claim 9 , wherein the fluid supplied by the fluid source comprises a radiopaque substance. 
     
     
         12 . The catheter of  claim 3 , wherein a proximal opening of the lumen is positioned at a distal portion of the catheter but proximal of the cup-shaped surface of the cutting element. 
     
     
         13 . The catheter of  claim 12 , wherein the proximal opening is positioned on the rotatable shaft. 
     
     
         14 . The catheter of  claim 13 , wherein the rotatable shaft comprises two or more proximal openings of the lumen. 
     
     
         15 . The catheter of  claim 13 , wherein the rotatable shaft comprises an impeller proximal of the proximal opening, the impeller forcing fluid into the proximal opening when the rotatable shaft is rotated. 
     
     
         16 . The catheter of  claim 15 , wherein the impeller has 1 to 10 turns. 
     
     
         17 . The catheter of  claim 12 , wherein the lumen has a distal opening on the cup-shaped surface of the cutting element. 
     
     
         18 . The catheter of  claim 17 , wherein the distal opening is positioned at a longitudinal axis of the cutting element. 
     
     
         19 . The catheter of  claim 1 , wherein a proximal opening of the lumen is positioned on the cutting element. 
     
     
         20 . The catheter of  claim 19 , wherein the proximal opening is positioned at an outer edge of the cutting element. 
     
     
         21 . The catheter of  claim 20 , wherein the cutting element has a cup-shaped surface, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction, and the lumen has a distal opening on the cup-shaped surface of the cutting element. 
     
     
         22 . The catheter of  claim 21 , wherein the distal opening is positioned at a longitudinal axis of the cutting element. 
     
     
         23 . The catheter of  claim 1 , wherein the tissue collection chamber comprises vent holes. 
     
     
         24 . The catheter of  claim 23 , wherein the tissue collection chamber comprises 10 to 200 vent holes. 
     
     
         25 . The catheter of  claim 23 , wherein the vent holes have a diameter of from 25 to 200 microns. 
     
     
         26 . The catheter of  claim 1 , wherein the cutting element is movable between a stored position and a cutting position relative to the opening. 
     
     
         27 . An atherectomy catheter, comprising:
 a body having an opening;   a rotatable shaft coupled to the body;   a tissue collection chamber coupled to the body and positioned distal to the cutting element;   a cutting element coupled to the rotatable shaft, the cutting element having a cutting edge; and   a part for propelling fluid distally in the tissue collection chamber, the part being selected from the group consisting of: (i) a drive shaft having a proximal end and a distal portion, the proximal end being attached to the cutting element and a propeller being attached to the distal portion; and (ii) a paddle attached to the cutting element.   
     
     
         28 . The catheter of  claim 27 , wherein the cutting element has a cup-shaped surface, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction. 
     
     
         29 . The catheter of  claim 28 , wherein the part for propelling fluid distally in the tissue collection chamber is selected from the group consisting of: (i) a drive shaft having a proximal end and a distal portion, the proximal end being attached to the cup-shaped surface of the cutting element and a propeller being attached to the distal portion; and (ii) a paddle attached to the cup-shaped surface of the cutting element. 
     
     
         30 . The catheter of  claim 27 , wherein the part for propelling fluid distally in the tissue collection chamber is a drive shaft having a proximal end and a distal portion, the proximal end being attached to the cutting element and a propeller being attached to the distal portion. 
     
     
         31 . The catheter of  claim 30 , wherein the propeller is located distally of the opening and proximally of the distal end of the collection chamber. 
     
     
         32 . The catheter of  claim 31 , wherein the propeller is located immediately distally of the opening. 
     
     
         33 . The catheter of  claim 31 , wherein the propeller is located in the distal half of the collection chamber. 
     
     
         34 . The catheter of  claim 30 , wherein the proximal end of the drive shaft is attached to a cup-shaped surface of the cutting element, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction. 
     
     
         35 . The catheter of  claim 27 , wherein the part for propelling fluid distally in the tissue collection chamber is a paddle attached to the cutting element. 
     
     
         36 . The catheter of  claim 35 , wherein the paddle is a wire that is twisted in a helical configuration. 
     
     
         37 . The catheter of  claim 36 , wherein the wire has a rectangular cross section. 
     
     
         38 . The catheter of  claim 36 , wherein the wire has a thickness from 0.002 to 0.020 inch (0.0051 to 0.051 cm). 
     
     
         39 . The catheter of  claim 36 , wherein the wire width is from 0.010 to 0.075 inch (0.025 to 0.19 cm). 
     
     
         40 . The catheter of  claim 36 , wherein the paddle has a wire width that is from 20 to 95 percent of an inside diameter of the collection chamber. 
     
     
         41 . The catheter of  claim 35 , wherein the paddle has a longitudinal length that is at least 50 percent of the longitudinal length of the collection chamber. 
     
     
         42 . The catheter of  claim 35 , wherein the paddle has a longitudinal length that is at least 70 percent of the longitudinal length of the collection chamber. 
     
     
         43 . The catheter of  claim 27 , wherein the tissue collection chamber comprises vent holes. 
     
     
         44 . The catheter of  claim 43 , wherein the tissue collection chamber comprises 10 to 200 vent holes. 
     
     
         45 . The catheter of  claim 43 , wherein the vent holes have a diameter of from 25 to 200 microns. 
     
     
         46 . The catheter of  claim 35 , wherein the paddle is attached to a cup-shaped surface of the cutting element, the cup-shaped surface being configured to re-direct tissue cut by the cutting edge in a distal direction when the cup-shaped surface moves in the distal direction. 
     
     
         47 . The catheter of  claim 27 , wherein the collection chamber comprises a portion at a distal end that can be opened to remove cut material and particles. 
     
     
         48 . The catheter of  claim 27 , wherein the cutting element is movable between a stored position and a cutting position relative to the opening. 
     
     
         49 . A method of recirculating fluid in an atherectomy catheter comprising:
 providing an atherectomy catheter, the atherectomy catheter comprising:
 a body having an opening; 
 a rotatable shaft coupled to the body; 
 a tissue collection chamber coupled to the body and positioned distal to the cutting element, the tissue collection chamber having vent holes; 
 a cutting element coupled to the rotatable shaft, the cutting element having a cutting edge; and 
   moving fluid out of the tissue collection chamber through the vent holes such that a negative pressure is created inside the tissue collection chamber and this negative pressure causing fluid to enter the tissue collection chamber through the opening of the body of the catheter.   
     
     
         50 . The method of  claim 49 , wherein the catheter comprises a lumen configured to direct fluid into the tissue collection chamber. 
     
     
         51 . The method of  claim 49 , wherein the catheter comprises a part for propelling fluid distally in the tissue collection chamber, the part being selected from the group consisting of: (i) a drive shaft having a proximal end and a distal portion, the proximal end being attached to the cutting element and a propeller being attached to the distal portion; and (ii) a paddle attached to the cutting element. 
     
     
         52 . A method of removing material from a body lumen, the method comprising:
 providing an atherectomy catheter, the atherectomy catheter comprising:
 a body having an opening; 
 a rotatable shaft coupled to the body; 
 a tissue collection chamber coupled to the body and positioned distal to the cutting element; 
 a cutting element coupled to the rotatable shaft, the cutting element having a cutting edge; and 
 a lumen configured to direct fluid into the tissue collection chamber; 
   placing the catheter in the body lumen; and   moving the catheter in the body lumen to contact the cutting element with the material in the body lumen.   
     
     
         53 . The method of  claim 52 , wherein the catheter is moved in a distal direction to contact the cutting edge with the material in the body lumen. 
     
     
         54 . The method of  claim 52 , wherein the catheter is placed in the body lumen with the cutting element in the stored position and the catheter is moved to contact the material with the cutting element in a cutting position. 
     
     
         55 . The method of  claim 52 , wherein the body lumen is a blood vessel. 
     
     
         56 . A method of removing material from a body lumen, the method comprising:
 providing an atherectomy catheter, the atherectomy catheter comprising:
 a body having an opening; 
 a rotatable shaft coupled to the body; 
 a tissue collection chamber coupled to the body and positioned distal to the cutting element; 
 a cutting element coupled to the rotatable shaft, the cutting element having a cutting edge; and 
 a part for propelling fluid distally in the tissue collection chamber, the part being selected from the group consisting of: (i) a drive shaft having a proximal end and a distal portion, the proximal end being attached to the cutting element and a propeller being attached to the distal portion; and (ii) a paddle attached to the cutting element; 
   placing the catheter in the body lumen; and   moving the catheter in the body lumen to contact the cutting element with the material in the body lumen.   
     
     
         57 . The method of  claim 56 , wherein the catheter is moved in a distal direction to contact the cutting edge with the material in the body lumen. 
     
     
         58 . The method of  claim 56 , wherein the catheter is placed in the body lumen with the cutting element in the stored position and the catheter is moved to contact the material with the cutting element in a cutting position. 
     
     
         59 . The method of  claim 56 , wherein the body lumen is a blood vessel.